Recently, in accordance with development of an IT technology, a field which uses a moving flight vehicle such as a drone has rapidly developed. Therefore, the drone is utilized not only for a military purpose but also for various fields including business and agriculture. Further, it is expected that the drone will be applied to many different fields in the future. For example, monitoring is performed using a drone. With regard to this, a route determining method which allows a moving object such as a drone to return via a plurality of destination nodes has been discussed.
When the moving object is sent to a plurality of destinations which are scattered over a wide region, a method of moving the shortest distance has been studied in the related art as a problem in which when n cities and a distance between cities are given, the shortest route that visits each city exactly once but visits all the cities is obtained, that is, as a traveling salesperson problem (TSP). However, as places to visit are increased, possible numbers of n! (=1*2*3* . . . (n−1)*n) need to be compared. Therefore, the complexity is increased and thus a computation time is significantly increased so that it is difficult to actually use the above-mentioned method. Further, as a heuristic algorithm, a nearest neighbor heuristic algorithm (NN) which sequentially visits nodes closer to the current location among nodes which are not visited is known as a practical alternative.
However, the above-mentioned moving route determining method only suggests a method which visits a plurality of destinations treated as points through the shortest route. In the case of a destination such as a sensor node having a predetermined communication distance, an object may be achieved only by accessing to be close to a predetermined point without directly visiting the predetermined point. The above-mentioned method does not suggest a method for treating the above-mentioned destination having a predetermined radius.